package com.zlsf.codec;




import com.zlsf.service.Jtt1078Decoder;
import com.zlsf.util.Packet;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;

/**
 * Created by houcheng on 2019-12-05.
 * ADPCM 和 PCM转换
 */
public final class ADPCMCodec extends com.zlsf.codec.AudioCodec {
  static int[] indexTable = {
    -1, -1, -1, -1, 2, 4, 6, 8,
    -1, -1, -1, -1, 2, 4, 6, 8
  };

  static int[] stepsizeTable = {
    7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
    19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
    50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
    130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
    337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
    876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
    2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
    5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
    15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
  };

  public static class State {
    public short valprev;
    public byte index;
  }

  public byte[] toPCM(byte[] data) {
    State state = new State();
    int dlen = data.length / 2;
    byte[] temp;
    // 如果前四字节是00 01 52 00，则是海思头，需要去掉，否则就视为普通的ADPCM编码
    if (data[0] == 0x00 && data[1] == 0x01 && (data[2] & 0xff) == (data.length - 4) / 2 && data[3] == 0x00) {
      dlen = (data.length - 8);
      temp = new byte[data.length - 8];
      System.arraycopy(data, 8, temp, 0, temp.length);

      state.valprev = (short) (((data[5] << 8) & 0xff00) | (data[4] & 0xff));
      state.index = data[6];
    } else {
      dlen = data.length - 4;
      temp = new byte[data.length - 4];
      System.arraycopy(data, 4, temp, 0, temp.length);

      state.valprev = (short) (((data[1] << 8) & 0xff00) | (data[0] & 0xff));
      state.index = data[2];
    }
    short[] outdata = new short[dlen * 2];
    adpcm_decoder(temp, outdata, dlen * 2, state);
    temp = new byte[dlen * 4];
    for (int i = 0, k = 0; i < outdata.length; i++) {
      short s = outdata[i];
      temp[k++] = (byte) (s & 0xff);
      temp[k++] = (byte) ((s >> 8) & 0xff);
    }
    return temp;
  }

  public byte[] fromPCM(byte[] data) {
    return null;
  }

  public static void adpcm_coder(short[] indata, byte[] outdata, int len, State state) {
    int val;      /* Current input sample value */
    int sign;      /* Current adpcm sign bit */
    int delta;      /* Current adpcm output value */
    int diff;      /* Difference between val and valprev */
    int step;      /* Stepsize */
    int valpred;    /* Predicted output value */
    int vpdiff;      /* Current change to valpred */
    int index;      /* Current step change index */
    int outputbuffer = 0;    /* place to keep previous 4-bit value */
    int bufferstep;    /* toggle between outputbuffer/output */

    byte[] outp = outdata;
    short[] inp = indata;

    valpred = state.valprev;
    index = state.index;
    step = stepsizeTable[index];

    bufferstep = 1;

    int k = 0;
    for (int i = 0; len > 0; len--, i++) {
      val = inp[i];

      /* Step 1 - compute difference with previous value */
      diff = val - valpred;
      sign = (diff < 0) ? 8 : 0;
      if (sign != 0) diff = (-diff);

      /* Step 2 - Divide and clamp */
      /* Note:
       ** This code *approximately* computes:
       **    delta = diff*4/step;
       **    vpdiff = (delta+0.5)*step/4;
       ** but in shift step bits are dropped. The net result of this is
       ** that even if you have fast mul/div hardware you cannot put it to
       ** good use since the fixup would be too expensive.
       */
      delta = 0;
      vpdiff = (step >> 3);

      if (diff >= step) {
        delta = 4;
        diff -= step;
        vpdiff += step;
      }
      step >>= 1;
      if (diff >= step) {
        delta |= 2;
        diff -= step;
        vpdiff += step;
      }
      step >>= 1;
      if (diff >= step) {
        delta |= 1;
        vpdiff += step;
      }

      /* Step 3 - Update previous value */
      if (sign != 0)
        valpred -= vpdiff;
      else
        valpred += vpdiff;

      /* Step 4 - Clamp previous value to 16 bits */
      if (valpred > 32767)
        valpred = 32767;
      else if (valpred < -32768)
        valpred = -32768;

      /* Step 5 - Assemble value, update index and step values */
      delta |= sign;

      index += indexTable[delta];
      if (index < 0) index = 0;
      if (index > 88) index = 88;
      step = stepsizeTable[index];

      /* Step 6 - Output value */
      if (bufferstep != 0) {
        outputbuffer = (delta << 4) & 0xf0;
      } else {
        outp[k++] = (byte) ((delta & 0x0f) | outputbuffer);
      }
      bufferstep = bufferstep == 0 ? 1 : 0;
    }

    /* Output last step, if needed */
    if (bufferstep == 0)
      outp[k++] = (byte) outputbuffer;

    state.valprev = (short) valpred;
    state.index = (byte) index;
  }


  public static void adpcm_decoder(byte[] indata, short[] outdata, int len, State state) {
    // signed char *inp;		/* Input buffer pointer */
    // short *outp;		/* output buffer pointer */
    int sign;      /* Current adpcm sign bit */
    int delta;      /* Current adpcm output value */
    int step;      /* Stepsize */
    int valpred;    /* Predicted value */
    int vpdiff;      /* Current change to valpred */
    int index;      /* Current step change index */
    int inputbuffer = 0;    /* place to keep next 4-bit value */
    int bufferstep;    /* toggle between inputbuffer/input */

    short[] outp = outdata;
    byte[] inp = indata;

    valpred = state.valprev;
    index = state.index;
    if (index < 0) index = 0;
    if (index > 88) index = 88;
    step = stepsizeTable[index];

    bufferstep = 0;

    int k = 0;
    for (int i = 0; len > 0; len--) {

      /* Step 1 - get the delta value */
      if (bufferstep != 0) {
        delta = inputbuffer & 0xf;
      } else {
        inputbuffer = inp[i++];
        delta = (inputbuffer >> 4) & 0xf;
      }
      bufferstep = bufferstep == 0 ? 1 : 0;

      /* Step 2 - Find new index value (for later) */
      index += indexTable[delta];
      if (index < 0) index = 0;
      if (index > 88) index = 88;

      /* Step 3 - Separate sign and magnitude */
      sign = delta & 8;
      delta = delta & 7;

      /* Step 4 - Compute difference and new predicted value */
      /*
       ** Computes 'vpdiff = (delta+0.5)*step/4', but see comment
       ** in adpcm_coder.
       */
      vpdiff = step >> 3;
      if ((delta & 4) > 0) vpdiff += step;
      if ((delta & 2) > 0) vpdiff += step >> 1;
      if ((delta & 1) > 0) vpdiff += step >> 2;

      if (sign != 0)
        valpred -= vpdiff;
      else
        valpred += vpdiff;

      /* Step 5 - clamp output value */
      if (valpred > 32767)
        valpred = 32767;
      else if (valpred < -32768)
        valpred = -32768;

      /* Step 6 - Update step value */
      step = stepsizeTable[index];

      /* Step 7 - Output value */
      outp[k++] = (short) valpred;
    }

    state.valprev = (short) valpred;
    state.index = (byte) index;
  }


  public static void main(String[] args) throws Exception {
    ByteArrayInputStream bais = null;
    ByteArrayOutputStream baos = new ByteArrayOutputStream(1024 * 1024 * 4);

    int len = -1;
    byte[] block = new byte[512];
    FileInputStream fis = new FileInputStream("d:\\test\\g711\\streamax.bin");
    FileOutputStream fos = new FileOutputStream("d:\\test\\g711\\111111111122222222222222.pcm");

    ADPCMCodec codec = new ADPCMCodec();

    Jtt1078Decoder decoder = new Jtt1078Decoder();
    while ((len = fis.read(block)) > -1) {
      decoder.write(block, 0, len);
      while (true) {
        Packet p = decoder.decode();
        if (p == null) break;

        int lengthOffset = 28;
        int dataType = (p.seek(15).nextByte() >> 4) & 0x0f;
        // 透传数据类型：0100，没有后面的时间以及Last I Frame Interval和Last Frame Interval字段
        if (dataType == 0x04) lengthOffset = 28 - 8 - 2 - 2;
        else if (dataType == 0x03) lengthOffset = 28 - 4;

        // FFMpegManager.getInstance().feed(publisherId, packet.seek(lengthOffset + 2).nextBytes());
        if (dataType == 0x00 || dataType == 0x01 || dataType == 0x02) {

        } else {
          byte[] data = p.seek(lengthOffset + 2).nextBytes();
          fos.write(codec.toPCM(data));
          fos.flush();
        }
      }
    }

    fos.flush();

    fis.close();
    fos.close();
  }

}
